# Determine The Speed of a Charge at a given point

Agent 337737

## Homework Statement

Given: The electric potential function: V= 3x^2 + 2xy +(y^2)z + 20
a) A 4 coulombs, 2kg charge is released from the origin. Determine the speed of the charge at (1,1,-1)

## Homework Equations

Kinetic Energy= 1/2 mv^2

## The Attempt at a Solution

I tried to use the fact that the change in potential energy is equal to the negative change in kinetic energy.
I calculated the change in electric potential to be 4 V and set that equal to the negative change in kinetic energy, which would just be -1/2 mv^2
However, when I solve for the velocity, I get the square root of negative 4. Have I done something wrong or is the problem just flawed?